I seem to go through this phase now and again.
Remind me why I'm doing this? It's not for the sales, because those are miniscule. The only consolation I have is that others are having slumpy sales as well. A few people I know are doing good with their careers, but mine seems to have stagnated.
I'm not sure what that is, but I have a suspicion that with KDP (Kindle Direct Publishing, a.k.a., self-publishing), there's a lot of books out there and it's getting harder and harder to find individual authors. I also think other forms of entertainment are taking a chunk out of budgets. Movies, TV, video games, etc. -- it's all entertainment, and how many people actually sit and read a book anymore?
Ultimately, I guess it doesn't matter. I'm a writer, and I'll write. I may not publish, but I'll write. I might not have a book out next year (shock!) because I'm shopping around for a publisher, but we'll see. Stranger things have happened. I'm going to spend 2015 on promo and see where that takes me. If I don't see an uptick in sales, then fine.
I'll write and have fun doing it, and to heck with publishing.